Hypertensive Disorders of Pregnancy with and Without Prepregnancy Hypertension Are Associated with Incident Maternal Kidney Disease Subsequent to Delivery

Abstract

Background: Maternal morbidity and mortality are related to prepregnancy hypertensive disease and hypertensive disorders of pregnancy (HDP) including preeclampsia (41.1% of HDP), eclampsia (1.3% of HDP), and gestational hypertension (39.9% of HDP). Less information is available on the risk of maternal kidney disease and potential racial/ethnic differences following a hypertensive condition during pregnancy. Our objective was to examine the relationships between HDP and prepregnancy hypertension with maternal incident kidney disease subsequent to delivery (up to 3, 5, and 14 years) with consideration of racial/ethnic differences. Methods: In a retrospective cohort study, 391 838 women 12 to 49 years of age had a live birth in South Carolina between 2004 and 2016; 35.1% non-Hispanic Black (NHB) and 64.9% non-Hispanic White (NHW). Hospitalization, emergency department, and birth certificate data defined prepregnancy hypertension and HDP. Hospitalization and death certificate data identified incident kidney disease. Results: 317 006 (80.8%) women experienced neither condition, 1473 (0.4%) had prepregnancy hypertension, 64 050 (16.3%) had HDP, and 9662 (2.5%) had both conditions (prepregnancy hypertension with superimposed HDP, ie, preeclampsia). Five years after delivery, incident kidney disease risk was increased for NHB and NHW women with HDP (NHB: hazard ratio, 2.30 [95% CI, 1.94-2.73]; NHW: hazard ratio, 1.97 [95% CI, 1.64-2.37]) and with both conditions (NHB: hazard ratio, 3.88 [95% CI, 3.05-4.93]; NHW: hazard ratio, 1.86 [95% CI, 1.20-2.87]) compared with counterparts with neither condition after adjustment (P value for race/ethnicity interaction=0.003). Conclusions: Increased kidney disease risk 5 years after delivery was observed for women with HDP and with both compared with neither condition, with associated risk higher in NHB than NHW women.